The stupid thing is if they were just going to put lorem ipsum instead of the actual text, they should've just stuck with the "folded corner" used in previous versions of windows mobile. The greeking is nearly invisible on my phone.

So is this a mistake or on purpose? Its a bit weird, and hasn't been fixed in Portico. Why Latin?

It's usually used when you first start building an app, you template it with dummy data and Visual Studio automatically gives you this Latin text in default projects. You are supposed to change it to something more useful before the app is released.

So is this a mistake or on purpose? Its a bit weird, and hasn't been fixed in Portico. Why Latin?

My guess would be on purpose, and my reason is because on the older phones (1st and 2nd gen WP7 phones), you can barely make out what's written. So it was a lazy way to show the month view without actually writing the actual appointments on it. Hopefully they fix this now that resolutions on the newer phones make them readable.
Edit: As I said before, the only way to make your voice heard is to vote for such features - http://windowsphone.uservoice.com/fo...-view-zoomable.

So is this a mistake or on purpose? Its a bit weird, and hasn't been fixed in Portico. Why Latin?

This is intentional and has been this way since Windows Phone launched. I can't find a link off hand, but there was an official explanation that the text on the calendar was never meant to be a small version of your appointments, just text indicating you had things on those days.

It's usually used when you first start building an app, you template it with dummy data and Visual Studio automatically gives you this Latin text in default projects. You are supposed to change it to something more useful before the app is released.

In this case the text was kept there in WP7 because supported screen resolutions were to low for the human to even read text at that size.

So, no, this was not them just leaving it by accident, it simply didn't matter and was used just to show a visual placeholder.

However with the release of WP8, the high rez screen support is here now and the human eye can actually read it. Whether that is an issue for users, I don't know. It doesn't bother me but obviously bothers others.